Studies on Bacterial Growth and Arsenic (III) Biosorption Using Bacillussubtilis

Abstract

Gram-negative bacteria Bacillus subtilis biosorps arsenic (III) ion from its aqueous solution. The maximum biosorption of lead is w = 97.30 · 10–2 within 72 h of inoculation time with optimum pH 3.5 and optimum temperature 40 °C for w = 500 · 10–6 initial loading of arsenic ion in a shake flask (optimum n = 60 min–1). 7 days old and = 30 · 10–2 inoculum culture is used in the studies. Arsenic (III) ion is measured by using atomic absorption spectrophotometer into an air-acetylene flame and absorbance is measured at 229 nm. The maximum bacterial growth is noticed as c = 3.90 · 108 cells mL–1 at optimum conditions. The bacteria can tolerate upto w = 600 · 10–6 of initial arsenic (III) ion loading. The Langmuir and Freundlich Isotherms fit the biosorption data reasonably well and played a major role in giving a better understanding of bioprocess modeling. The Monod Model for bacterial growth shows that the specific growth rate () of B. subtilis in the initial w = 500 · 10–6 of arsenic (III) ion loading, is found to be 0.017 s –